If your multiplicity of infection (MOI) is low, you can be fairly certain according to the Poisson distribution that you will have only one phage per cell. If MOI is high then more phage can infect at once. Helper phage cannot replicate, but are added at a high MOI to ensure rescue of all displaying phage.

If your multiplicity of infection (MOI) is low, you can be fairly certain according to the Poisson distribution that you will have only one phage per cell. If MOI is high then more phage can infect at once. Helper phage cannot replicate, but are added at a high MOI to ensure rescue of all displaying phage.